The present invention relates to a new and improved construction of a group control for elevators or the like.
Generally speaking, the group control for elevators or the like according to the invention comprises at least one storey call storage which can be controlled by means of storey call transmitters, cabin call storages correlated to each cabin of the group and which can be controlled by means of cabin call transmitters. Further, there are provided selectors correlated to each elevator of the group which indicate that storey at which the cabin still could stop, and load measuring devices correlated to each cabin as well as a scanner device for each storey which possesses at least one position. Each elevator is provided with a computer device possessing an adder, the computer device forming from at least the distance between a considered storey and the selector position, the number of intermediate stops to be expected within such distances predicated upon existing cabin and allocated storey calls as well as the momentary cabin load a time proportional sum corresponding to the service capability of a cabin of the group with respect to the considered storey. At least one comparison device or comparator is provided by means of which the cabin having the lowest servicing cost corresponding to the smallest previously computated loss time and therefore optimum service capability can be allocated to the considered storey or floor.
With such type control as has been disclosed in U.S. Pat. No. 3,511,342 a call determining device possessing a ring counter brings the storey calls contained in the storey call storage or memory into a sequence in which they can be successively allocated by means of a call distributor to the individual cabins of an elevator group. The call distributor examines all of the cabins at the same time and selects that cabin which possesses an optimum servicing or employment capability for the related call, wherein the servicing capability is expressed by a time-proportional signal dependent upon a number of factors. The call distributor contains a finder, for instance in the form of a further ring counter which possesses the finding or seeking positions corresponding to the storey calls. Upon presence of a call selected by the call determining device the finder is placed into operation starting from the related storey, and the storey is found in steps. Upon coincidence of the finder and cabin position there is stored in a distance register a number corresponding to the spacing between the calls site and the cabin, and there is taken into account whether one is concerned with a travel direction command or a free cabin. The determined number is converted into an analogue signal, corresponding to the time needed by the cabin for the relevant distance. This signal is infed to a summation circuit which determines the servicing capability of the cabin.
During the searching or finding operation up to the cabin there is determined by means of coincidence of the finder position and the storey for which there has been stored the storey call or cabin call, the number of intermediate stops and accumulated in an intermediate stop counter. The counter converts this number into an analogue time signal, which likewise is infed to the summation circuit. In the same manner during the complete finding cycle there is determined the total number of stops and there is infed an appropriate analogue time signal at the end of the finding operation to the summation circuit. In a load determination device there is produced a fourth time signal proportional to the cabin load and likewise fed into the summation circuit.
The output signal of the summation circuit which is formed from the existing four signals is infed to a comparison element. A ramp signal which is generated at the end of the searching or finding operation by a ramp signal generator and which increases with time likewise is infed to the comparison element. Upon coincidence of the signals of a comparison element of a cabin there is accomplished the allocation by storing the selected storey call in a requirement storage correlated to the cabin, and in each case there is strived for the coincidence at the cabin with the smallest time-proportional output signal of the summation circuit and therefore optimum cabin servicing or employment capability.
If the selected storey call is not serviced during a time span controlled by a call time measuring device, then it is extinguished in the requirement storage of the relevant cabin and for the purpose of new allocation is infed to the call determining device and from such to the call distributor.
With the previous group control there are determined for the computation of the time loss of a passenger waiting at the considered storey or floor the time losses caused by the travel time of the cabin and the intermediate stops. The time losses of the travelling guests within the elevator cabin, arising due to stop at such storey, however are only insufficiently taken into account, since the cabin load which no longer exists at the servicing time point owing to possible future entering and exiting passengers and determined at the computation time point are basically incorporated into the time loss computation. With these factors it is only possible with extreme difficulty to optimize the call allocation, because the future arising load changes during progressive approach of the cabin at the considered storey due to the exiting and entering passengers is not determined during the computation during the loss times. Furthermore, it is disadvantageous that the storey calls are only then first allocated when they are infed to the call distributor in accordance with the sequence determined by the call distributor and to be performed according to the computation, so that there can arise delays in the allocation.